Infineon 18 fet and kelly KLS7218S controllers on an electric bike
An article for those who already know a little about the topic.
It would seem, well, one controller, well, another - what's the difference? power is about the same, the differences are in small details. However, not all so simple.
Initially, I set myself this controller:
because many people recommended it for a 3 kW motor-wheel (I have one).
This controller is not "sinus", the shape of its signal to the motor is a trapezoid. This causes it to run louder than usual, and this controller also controls the motor based on the motor's rotational speed. It would seem so what? And the fact that when you turn the throttle slightly, there is a sharp jerk, albeit for a short time, but it is very dangerous when you need to rev a little in a narrow place. To alleviate this problem slightly, this controller supports a 3-position "speed" switch, which not only limits the maximum speed but also limitsdelivers current to the motor. In practice, driving without this switch is very dangerous. The most common mistake is accidentally twisting the throttle when you think the power is off. The bike will take off like a rocket and drag you along, it will end with injuries. With a motor with a power of more than 1 kW, it is unrealistic to hold it with your hands.
Something like this happened to me, after which I decided to try another controller, this time sinusoidal and controlled by current, not by speed. Here's one:
I spent a week replacing all the connectors for a new controller and installing this controller in place of the old one. Tried to get out. Yeaaaa..... It's a completely different driving experience. The starts are smooth, the throttle is predictable, I really liked it. For this controller, a three-position switch is essentially not needed, a throttle stick is enough. It should be noted that all sine controllers turn electric motors a little slower than non-sine controllers, by about 15%, which means that the maximum speed will be lower. But a smooth start, the presence of bluetooth connection with the phoneto view motor data online, the small size all outweighs the reduction in top speed.
IMHO, controllers without soft start are suitable for motors up to 1 kW, so they are not able to cause significant harm from an accidental start when the rider is not ready for it.
A few photos of installing a new controller on my bike: